msem-instigator

Tempting Realms enters tapped unless you control two or more other lands.
{T}: Add {B}.
{T}, Pay 1 life: Add {U} or {R}.

Treacherous Den enters tapped.
{T}: Add {B} or {R}.
{2}{B}{R}, {T}, Sacrifice Treacherous Den: Draw a card.

Schoolmaster gets +1/+1 for each other Merfolk you control.
When Schoolmaster enters, create a 1/1 white Merfolk creature token.

Flying (This creature can't be blocked except by creatures with flying or reach.)
At the beginning of your upkeep, put a +1/+1 counter on Fleshrender Demon and you lose 1 life.

Golden age (If you cast an instant or sorcery spell, activated a nonmana ability, and attacked this turn, enter a renaissance for this game.)
{2}{R}{G}{W}: You may put a creature card from your hand onto the battlefield. It gains haste and vigilance until end of turn. At the beginning of the next end step, return it to your hand unless you're in a renaissance.

Crafted Coast enters tapped unless another player controls a land that could produce {W} or {U}.
{T}: Add {W} or {U}.

Indestructible
Ghrin-Danu, the Dawnhart can't attack or block unless you control three other creatures with different powers.
Whenever you attack, put a +1/+1 counter on up to one other target creature you control.

{T}: Add {C}.
{5}, {T}: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.

Tap up to two target creatures.
Leitmotif (If you cast this spell from your hand, exile it as it resolves. When you next cast a spell that shares a color with this card, you may cast this from exile without paying its mana cost.)

Flying
When Illusionary Steed becomes the target of a spell or ability, sacrifice it.

Whenever equipped creature deals combat damage to a player, create a 1/1 colorless Thopter artifact creature token with flying.
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Undine Coven gets +1/+1 for each other Merfolk you control.
Whenever you cast a noncreature spell, Undine Coven deals 1 damage to target player or planeswalker.

When Hand of Fidelity enters, creatures you control get +1/+1 until end of turn.
At the beginning of your upkeep, if your fealty to Plains is five or greater, transform Hand of Fidelity. (Each Plains you control counts towards your fealty to Plains.)

When this creature enters, create a 2/2 black Zombie creature token. That token seeks secrets and gains haste until end of turn. (Give it that Oath Aura. Fulfill it by attacking with it and two or more other creatures to draw a card.)

Whenever another creature you control dies, put a +1/+1 counter on Belligerent Mob.

(Add a quest counter as this enters. Sacrifice after 3.)
Whenever you put one or more +1/+1 counters on a creature, add a quest counter.
1, 2 — Create two 1/1 green and white Mouse Soldier creature tokens with vigilance.
3 — Until end of turn, creatures you control get +1/+1 and gain lifelink.

Vision (Whenever this or another creature you control enters, reveal the top card of your library. Then you may put that card into your graveyard.)
Whenever Gleaming Rider envisions an instant or sorcery card, target creature becomes a 5/5 Elk Spirit until end of turn.

Each player sacrifices three lands. Regal Ignition deals 3 damage to each nonlegendary creature.

When Prophetic Prismite enters, draw a card.
{2}: Add one mana of any color.

At the beginning of your first main phase, exile target card in a graveyard. If it's a creature card, put a +1/+1 counter on target creature you control. If it's a land card, add {C}. If it's a noncreature, nonland card, you gain 3 life.

Creatures you control get +2/+1 until end of turn. Citizens and Peasants you control gain first strike until end of turn.

When Lunar Vigil enters, draw a card, then scry 2.
If you would draw one or more cards, you may instead put a night counter on Lunar Vigil and draw that many cards minus one.
Sacrifice Lunar Vigil: Target player draws a card and adds {R} for each night counter on it.

Menace
When Selfserving Ghul enters, remove two counters from target permanent.

Create a 1/1 white and black Badger Cleric creature token with lifelink. (Then exile this card. You may cast the creature later from exile.)

Whenever Lackeybot deals damage to a player, choose an artifact card with mana value X or less at random, where X is the amount of damage dealt. You may create a token that's a copy of that card.